THERMAL SCIENCE

International Scientific Journal

Nandhakumar Shankar

,

Satheesh Kumar Vijayam

,

Chandrasekaran Keerthivasan Kunjupillai

,

Raju Kandasamy

NUMERICAL ANALYSIS OF THERMAL AND FLOW CHARACTERISTICS IN LOUVERED FIN HEAT EXCHANGERS WITH NOVEL FIN DESIGNS

ABSTRACT
This study presents the design and performance evaluation of novel louver fin geometries aimed at improving the air-side thermo-hydraulic performance of compact heat exchangers. While prior research has primarily explored traditional fin configurations, a significant gap remains in systematically analysing the impact of unconventional fin shapes and geometry dimension modifications. To address this, several innovative fin geometries were developed and assessed using computational fluid dynamics (CFD) under turbulent flow conditions. The performance metrics were evaluated across a Reynolds number range of 125-945, with a focus on the Colburn j-factor and friction factor (f-factor) to quantify heat transfer enhancement and pressure drop. While higher Reynolds numbers improved heat transfer and Nusselt number, gains tapered off at extreme flow rates. It was observed that optimized geometric configurations (the 120° louver angle with 20% pitch) led to a significant enhancement in heat transfer characteristics (high ℎ, Nu, and j) while maintaining a relatively low pressure drop and friction factor (ΔP and f). These trends clearly indicate a favourable thermal-hydraulic performance. The study is offering an effective approach for optimizing heat exchanger efficiency in air-cooled applications.
KEYWORDS
Louver Fin Geometry, CFD simulation, Heat Transfer Enhancement, Novel Fin Design, compact heat exchanger
PAPER SUBMITTED: 2025-08-03
PAPER REVISED: 2025-11-25
PAPER ACCEPTED: 2025-12-05
PUBLISHED ONLINE: 2026-02-08
DOI REFERENCE: https://doi.org/10.2298/TSCI250803005S
REFERENCES
[1] Kays, W.M. and London, A.L., Compact heat exchangers, (1984)
[2] Shah, R.K., Sekulić, D.P., Fundamentals of Heat Exchanger Design, John Wiley & Sons, Hoboken, NJ, USA, 2003
[3] Shah, R. K., Comprehensive Study of Heat Exchangers with Louvered Fins in Heat Exchangers - Advanced Features and Applications, Springer, New York, 2020
[4] Chand, S. and Chand, P., Parametric study on the performance of solar air heater equipped with louvered fins. Journal of Mechanical Science and Technology, 32 (2018), pp.3965-3973., 10.1007/s12206-018-0747-y
[5] Sønderby., et al., Thermal-hydraulic performance of a corrugated cooling fin with louvered surfaces. Energy Procedia, 142 (2017) pp. 4077-4084., 10.1016/j.egypro.2017.12.328
[6] Lin, C.W. and Jang, J.Y., 3D Numerical heat transfer and fluid flow analysis in plate-fin and tube heat exchangers with electrohydrodynamic enhancement. Heat and mass transfer, 41(7) (2005), pp.583-593., 10.1007/s00231-004-0540-6
[7] Moosavi, R., et al., Investigation of the geometrical structure of louvered fins in fin-tube heat exchangers for determining the minimum distance of the headers. Journal of Mechanical Science and Technology, 35(2021), pp.1721-1731., 10.1007/s12206-021-0335-4
[8] Kim, Nae-Hyun. Air-side heat transfer and pressure drop of the fin-and-tube heat exchangers having oval tubes under wet condition. Heat and Mass Transfer, 57, no. 10 (2021), pp.1633-1644., 10.1007/s00231-021-03058-1
[9] Kannadhasan, V., et al., Experimental research and CFD analysis on engine fins with varied geometries. Interactions, 245, no. 1 (2024): 260., 10.1007/s10751-024-02101-x
[10] Achaichia, A and Cowell, T.A, Heat transfer and pressure drop characteristics of flat tube and louvered plate fin surfaces, International Journal of Heat and Mass Transfer, 31 (1988), pp. 119-128
[11] Kim, M.H. and Bullard, C.W., Air-side thermal hydraulic performance of multi-louvered fin aluminum heat exchangers. International journal of refrigeration, 25(3) (2002), pp.390-400
[12] Wongwises, Somchai, and Yutasak Chokeman. Effect of fin thickness on air-side performance of herringbone wavy fin-and-tube heat exchangers. Heat and mass transfer, 41 (2004) pp. 147-154., 10.1007/s00231-004-0507-7
[13] Li, Yong, et al., Effect of shape and placement of twisted pin fins in a rectangular channel on thermo-hydraulic performance. Journal of Thermal Science, 33, no. 5 (2024), pp. 1773-1793., 10.1007/s11630-024-2030-0
[14] Zhu, Yuxi, and Yan Qiu. Comparison of thermal performance between annular fins and longitudinal fins in latent heat storage unit. Journal of Thermal Science, 32, no. 3 (2023), pp. 1227-1238., 10.1007/s11630-023-1731-0
[15] Mozafarie, Seyed Shahab, and Kourosh Javaherdeh. "Numerical design and heat transfer analysis of a non-Newtonian fluid flow for annulus with helical fins. Engineering Science and Technology, an International Journal, 22, no. 4 (2019), pp. 1107 -1115., 10.1016/j.jestch.2019.03.001
[16] Lindqvist, Karl, et al., "Plate fin-and-tube heat exchanger computational fluid dynamics model. Applied Thermal Engineering, 189 (2021), pp. 116669., 10.1016/j.applthermaleng.2021.116669
[17] Mercan, Hatice, et al., Determination of heat transfer rates of heavy-duty radiators for trucks having flattened and double-U grooved pipes with louvered fins by ANN method: an experimental study. The European Physical Journal Plus, 137, no. 3 (2022), pp. 382
[18] Santosa, IDewa MC, et al., Experimental and CFD investigation of overall heat transfer coefficient of finned tube CO2 gas coolers. Energy Procedia, 161 (2019), pp. 300-308., 10.1016/j.egypro.2019.02.096
[19] Li, Jun, et al., Effect of flow maldistribution on heat transfer performance and temperature field of plate-fin heat exchangers. International Communications in Heat and Mass Transfer, 149 (2023) pp. 107135., 10.1016/j.icheatmasstransfer.2023.107135
[20] Arunkumar, H. S., et al., Energy exergy and economic analysis of a multiple inlet solar air heater for augmented thermohydraulic performance. Applied Thermal Engineering, 246 (2024), pp. 122981., 10.1016/j.applthermaleng.2024.122981
[21] Kumar, S. et al., Optimization of louver fin geometries for miniature microchannel condenser by Taguchi and CFD method. Sādhanā, 49, no. 3 (2024) pp. 216., 10.1007/s12046-024-02558-0
[22] Malapure, V. et al., Numerical investigation of fluid flow and heat transfer over louvered fins in compact heat exchanger. International journal of thermal sciences, 46, no. 2 (2007), pp. 199-211., 10.1016/j.ijthermalsci.2006.04.010
[23] Erbay, L. Berrin, et al. Numerical investigation of the air-side thermal hydraulic performance of a louvered-fin and flat-tube heat exchanger at low Reynolds numbers, Heat Transfer Engineering, 38.6, (2017), pp. 627-640
[24] Feleke, Dessalew Shite et al., Numerical investigation of louver edges effect on the performances of louvered fin compact heat exchanger. Heliyon, 10, no. 6 (2024)., 10.1016/j.heliyon.2024.e27254
[25] Reshaeel, Muhammad, et al., A critical review of the thermal-hydraulic performance of fin and tube heat exchangers using statistical analysis. International Journal of Thermofluids, 24 (2024): 100858., 10.1016/j.ijft.2024.100858
[26] Li, Yang, et al., Multi-objective shape characterization of airside performance in sinusoidal wavy fin-and-tube heat exchangers with large-diameter tubes using CFD. Journal of Mechanical Science and Technology, 38, no. 7 (2024), pp. 3837-3848., 10.1007/s12206-024-0652-5
[27] Kim, Seong-Bhin, et al., Experimental performance evaluation of air-based photovoltaic-thermal collector with rectangular turbulators and longitudinal fins. Energy Reports, 12 (2024), pp. 1315-1324., 10.1016/j.egyr.2024.07.038
[28] Hassan, Jannah Haitham, and Vinous M. Hameed. "Evaluate the hydrothermal behavior in the heat exchanger equipped with an innovative turbulator. South African Journal of Chemical Engineering, 41 (2022), pp. 182-192., 10.1016/j.sajce.2022.06.003
[29] Jayranaiwachira, Nuthvipa, et al., Heat transfer analysis in a tube contained with louver-punched triangular baffles. Results in Engineering, 22 (2024), pp. 102276., 10.1016/j.rineng.2024.102276
[30] Hasan, Md Jahid, et al., Improvement of an exhaust gas recirculation cooler using discrete ribbed and perforated louvered strip vortex generator. International Journal of Thermofluids, 13 (2022), pp. 100132., 10.1016/j.ijft.2022.100132
[31] Zhang, Jinglong, et al., Effects of rectangular wing vortex generators on the thermal-hydraulic performance of louvered fin and flat tube heat exchanger. Journal of Thermal Science, 32, no. 2 (2023), pp. 628-642., 10.1007/s11630-023-1763-5
[32] Duarte, Rafael MD, et al., Numerical investigation of heat transfer enhancement by using louvered-winglet vortex generators mounted in a solar air heater channel-type. Journal of Thermal Analysis and Calorimetry, 148, no. 24 (2023), pp. 14183-14204., 10.1007/s10973-023-12599-y
[33] Alshibil, Ahssan MA, et al., Experimental performance comparison of a novel design of bi-fluid photovoltaic-thermal module using Louver fins. Energy Reports, 9 (2023), pp. 4518-4531., 10.1016/j.egyr.2023.03.110
[34] Ali, Samer, et al., Advancing thermal performance through vortex generators morphing. Scientific Reports, 13, no. 1 (2023), pp. 368., 10.1038/s41598-022-25516-4
[35] Dogan, Bahadır, et al., An experimental comparison of two multi-louvered fin heat exchangers with different numbers of fin rows, Applied Thermal Engineering, 91 (2015), pp. 270-278
[36] Sen, Palash, et al., Heat transfer enhancement of air flow through new types of perforated dimple/protrusion fins. Applied Thermal Engineering, 256 (2024), pp. 124030., 10.1016/j.applthermaleng.2024.124030
[37] Alnakeeb, Mohamed A., et al., Numerical investigation of thermal and hydraulic performance of fin and flat tube heat exchanger with various aspect ratios. Alexandria Engineering Journal 60, no. 5 (2021), pp. 4255-4265., 10.1016/j.aej.2021.03.036
[38] Shaeri, Jalil, et al., Effects of External Louvers on Solar Heat Gain and Energy Consumption of an Office Building in Different Climates of Iran. Iranian Journal of Science and Technology, Transactions of Mechanical Engineering, (2022), pp. 1-16., 10.1007/s40997-021-00449-x
PDF VERSION [DOWNLOAD]
Numerical analysis of thermal and flow characteristics in louvered fin heat exchangers with novel fin designs

© 2026 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence